Perorally insertable gastroesophageal anti-reflux valve prosthesis and tool for implantation thereof

ABSTRACT

Disclosed is an instrument, valve prosthesis and procedure for the minimally invasive implantation of an anti-reflux valve in a patient for the treatment of gastroesophageal reflux disease. Self-anchoring or stapleable one-way anti-reflux valve prostheses are provided, which may be implanted proximate a patient&#39;s gastroesophageal junction without open or laparoscopic surgery. An instrument for the peroral insertion, positioning and fixing of the valve prosthesis to the tissue of the esophagus is described for the implantation of either the self-anchoring or stapleable prosthesis.

FIELD OF THE INVENTION

This invention relates to a device and non-invasive surgical method fortreating gastroesophageal reflux disease. More specifically, it relatesto an anti-reflux valve prosthesis and associated instrumentation forits peroral placement and in situ fixing at the gastroesophagealjunction, to prevent the reflux of gastric contents into the esophagusin the treatment of gastroesophageal reflux disease in a patient.

BACKGROUND OF THE INVENTION

Gastroesophageal reflux disease (GERD) is the commonest cause ofdyspepsia, affecting some 30% of the United States adult populationintermittently and some 10% on a continuous and troublesome basis.Gastroesophageal reflux disease produces heartburn, abdominal pain andregurgitation of acid-containing gastric contents into the esophagus andpharynx. It may also lead to alteration of the lining of the esophagus(Barrett's Esophagus), which may go on to produce esophageal cancer.Current methods of treating GERD include powerful antacid medicationtherapies and surgical interventions.

Medication therapy with powerful antacids is directed at treating thesymptoms of GERD, and is necessarily not curative. Furthermore,medication-based therapies are not always fully effective, as reflux isnot prevented and the esophagus may continue to be exposed to gastriccontent.

Surgical intervention typically involves either open surgery (performedthrough the abdomen or the chest) or laparoscopic surgery (performedthrough one or more incision access ports inserted through the abdominalwall), and the re-sectioning of tissue or the implanting of a prostheticdevice. Although surgical interventions can be curative, thesetreatments are seriously invasive and have the attendant risk of suchprocedures. Despite the risk, the field has been motivated to providesolutions to the GERD problem, which has resulted in the development ofa number of surgically implantable anti-reflux valve prosthetic devices.Prior anti-reflux valve prostheses are essentially one-way valvesimplanted at the gastroesophageal junction using open or laparoscopicsurgery. The implanted prosthesis allows normal swallowing to take placein an orthograde manner while preventing the reflux of gastric contentsfrom the stomach into the esophagus.

Examples of surgically implanted esophageal anti-reflux valve prosthesesinclude the devices of: Godin (U.S. Pat. No. 5,314,473) which disclosesa one-way, anti-return valve comprising a flattened tubular partassociated with an annular fixing element; and Reich (U.S. Pat. No.4,846,836) which discloses a bi-directional valve and housing forsimilar purposes. These devices were developed to be inserted into thegastro-esophageal junction via open or laparoscopic surgery and fixedthere. The purpose was to permit the unidirectional passage of ingestedmaterials into the stomach while preventing the reflux of gastriccontent of the stomach into the esophagus. Typically, these devicesrequire suturing or other means to fix them to the tissue of theesophagus.

Generally, all of these prior devices and methods require surgicalinvasion of a body cavity and breach of the body membrane in somefashion (e.g., open surgery or laparoscopy) in order to accomplish theirutility. However, such invasive surgical interventions are toofrequently complicated by problems such as stricture formation, “gasbloat,” or recurrent symptoms of reflux disease. Additionally, theresults obtained by gross surgical treatment can be technique-dependentand vary significantly from surgeon to surgeon.

In view of the preference for minimally invasive forms of surgery thereis a need in the art for GERD treatments which can be fully accomplishedwithout surgically compromising the integrity of a patient's bodymembrane. Applicant has invented a peroral procedure for the insertionand implantation of an anti-reflux valve prosthesis that can addressthis need. It benefits the field to have an alternative prostheticdevice and method that can be practiced to position and fix ananti-reflux prosthesis in place in the esophagus without resort tosurgical incision or laparoscopy.

SUMMARY OF THE INVENTION

The present invention relates to an anti-reflux valve prosthesis systemfor treating gastroesophageal reflux disease (GERD) in a patient, whichdoes not require open or laparoscopic surgery to implant. The presentinvention provides for perorally inserting an anti-reflux valveprosthesis down the lumen of the esophagus, to the gastroesophagealjunction, where it is fixed in place. The advantage of this system isthat peroral insertion of such a valve eliminates the need for eitheropen formal laparotomy, thoracotomy or a laparoscopic approach usingmultiple access ports. Peroral installation of an anti-reflux prosthesishas the potential benefits of reducing the trauma, morbidity andhospital stay associated with implantation of anti-reflux valveprostheses relative to other surgical techniques. Furthermore, a systempermitting the implantation of a standardized anti-reflux valve in anaccurate and reproducible manner has the potential for providing moreconsistent clinical results than can be achieved with othertechnique-dependent methods of treatment.

The prosthesis system comprises an anti-reflux valve prosthesis and aperoral implantation tool for positioning and fixing the prosthesisproximate the distal end of the esophagus of a patient being treated forGERD. The present invention provides a prosthesis that isself-anchoring, having a mounting ring preferably constructed of amemory material supporting an anti-reflux valve. The memory materialallows the mounting ring to be acted upon and deformed, but to return toits original shape when the deformation force is removed. The mountingring is deformed during installation, but automatically returns to itsoriginal ring shape upon release. Also, the mounting ring incorporatestissue anchors which fixably engage the adjacent lumenal tissue of theesophagus to hold the prosthesis in place after installation. Ananti-reflux valve is supported by the mounting ring. The anti-refluxvalve is a normally closed, compliant one-way valve integral with themounting ring. A variety of one-way valve types are practicable in thepresent invention by one of ordinary skill in the art. These includesleeve valves, monocuspid, bicuspid and tricuspid valves, hinged diskvalves, double hinged valves and heart valves. Typically, the compliantpart of a valve has structural supports to prevent the valve frominverting.

A feature of one installation tool is a removable compression collar forencircling the mounting ring and holding it in a compressed conditionand for releaseably housing the prosthesis during positioning and priorto implantation. The compression collar is integral with one end of anovertube. The overtube is of a smooth and optionally flexibleconstruction. The distal end of the overtube receives and holds theprosthesis in a compressed configuration during positioning of theprosthesis in the lumen of the esophagus. A further feature of theinstallation tool is a hollow stylet tube indwelling and slidable in thelength of the overtube from the prosthesis at the distal end of theovertube to the handle at the proximal end of the overtube. At itsdistal end, the stylet is fitted with a normally deflated balloon whichis inflatable by passing a gas or liquid (under appropriate pressure)through the hollow of the stylet tube and into the balloon. The deflatedballoon is positioned and disengaged from the overtube in concert withthe prosthesis. After disengagement, the balloon is inflated to exertpressure on the inside surface of the mounting ring of the prosthesis.The recovery of the memory material of the released mounting ring andthe force exerted by the inflated balloon cause the tissue anchors ofthe mounting ring to engage with the lumenal tissue of the esophagus.

Another aspect of the present invention is a method for using the abovetool to implant an anti-reflux valve prosthesis in a patient with GERD.In operation, a compressed prosthesis, housed in the compression collarof the implantation tool, is inserted down the esophagus of ananesthetized patient. When the prosthesis is in a proper position forimplantation in the esophagus, the stylet and overtube are slidablypositioned so as to disengage the overtube and compression collar fromthe compressed prosthesis while holding it in position. Upondisengagement, the prosthesis is allowed to autoexpand into position.Then the balloon feature of the stylet is inflated to positively engagethe tissue anchor features of the prosthesis with the tissue of theesophagus. After the prosthesis is anchored in position, the balloon isdeflated and the implantation tool is removed from the patient.

Another aspect of the present invention is an anti-reflux valveprosthesis system having an implantation tool that uses a circularsurgical stapler to anchor an anti-reflux valve prosthesis in place in apatient's esophagus. The prosthesis is fixed in position by stapling amounting ring integral with a one-way valve to the lumen wall of theesophagus. The stapler is accomplished by adapting any of a number ofcircular surgical staplers known in the art (such as in U.S. Pat. No.5,445,644 to Pietrafitta et al., U.S. Pat. No. 5,411,508 to Bessler, andU.S. Pat. No. 5,104,025 to Main et al. which are hereby incorporatedherein by reference) to include the vacuum tissue engagement means ofthe present invention.

In this embodiment, the installation tool has a tubular body having alength and outside diameter appropriate for passage through the mouthand down the esophagus. A substantially typically circular surgicalstapler is mounted on the distal end of this tubular device. The stapleris comprised of four major features: (1) a head for dispensing anddriving staples, (2) an anvil for receiving and bending staple points,(3) a tissue engager for engaging and holding lumenal tissue in anannular space between the head and anvil, and (4) a prosthesis holderfor juxtaposing the mounting ring of a prosthesis with the engagedlumenal tissue. The relationship of these features is designed for thedriving of staple points through the lumenal tissue and the mountingring to fixably engage the two by then bending the staple points closedagainst the anvil. Typically, the head contains a series of stapleswhich can be driven by activation of a handle operated outside thepatient's mouth to drive the staples through the esophageal tissue toengage the mounting ring of the prosthesis. Force supplied to thesestaples drives them through the esophageal tissue, the mounting ring andagainst an anvil which bends the staples into a closed configuration tofix the tissue with the mounting ring.

The tissues to be stapled are drawn between the head and the anvil, bysuction applied to a tubular member disposed between the head and anvil.Once the tissue is drawn between the head and anvil, activation of thehandle of the tool sets the staples to permanently fix prosthesis inposition in the esophagus. Withdrawal of the tool leaves the prosthesispermanently implanted in the esophagus. There the prosthesis willprevent reflux from occurring. The suspension ring is constructed of anappropriate material of sufficient strength and long term durability toenable the device to be permanently fixed in situ.

The present invention also provides a kit for treating gastroesophagealreflux disease comprising an autoclaveable container containing theprosthesis system described, and optional instructions for its use.

The valve prosthesis of the present invention is constructed of knownmaterials, biologically inert and resistant to the media of stomachcontent. The prosthesis comprises a mounting ring and integralanti-reflux valve. The anti-reflux valve is an easy-opening one-wayvalve, implanted so that ingested materials may pass through it in anorthograde direction without significant impediment to their passage.The valve is normally closed, and the pressure differential between thestomach and the esophagus and between the abdominal and thoraciccavities act to maintain closure of the valve.

The mounting ring is typically made of a memory material (such as anickel titanium alloy, spring steel, or suitable plastic). Similardevices, but without the incorporation of an anti-reflux valve, areknown in the art and have been used in the treatment of strictures dueto esophageal cancer. The memory material of the mounting ring typicallyis encased or encapsulated in a suitable biologically and chemicallycompatible or inert material such as silicone or the like.

In one embodiment of the prosthesis, the mounting ring (from which thevalve is suspended) has an outwardly disposed, axial array of tissueanchors, typically, barbed spikes. When the mounting ring is properlypositioned in the esophagus, the tissue anchors are implanted into thelumen wall of the esophagus, to fix the mounting ring/valve combinationin place. The prosthesis (combination mounting ring and valve) isimplanted using an implantation tool described above.

In a further aspect of the present invention, a prosthesis comprises ananti-reflux valve housed inside a cylindrical device made of a memorymaterial which can be fixed in the distal esophagus. Such cylindricaldevices have been used (without the incorporation of a valve prosthesis)in the treatment of strictures due to esophageal cancer. An example ofsuch a device is the WALLSTENT® esophageal endoprosthesis (SchneiderUSA, Inc.). These devices typically comprise a cylinder of memory metalin close contact with a sleeve of suitable material, such as silicone.The prosthesis is inserted perorally and positioned using an adaptationof the usual tool used for installing such devices. The prosthesis isfixed in place by the expansion of the cylindrical device housing theanti-reflux valve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C are views of an anti-reflux valve prosthesis of thepresent invention showing the side, front and top of the prosthesis,respectively.

FIGS. 2A and 2B show self-mounting anti-reflux valve prostheses having(A) a single row array of tissue anchors and (B) a double rowed array oftissue anchors radially disposed and projecting outwardly from themounting ring.

FIGS. 3A and 3B are perspective views of an alternative prosthesis ofthe present invention (A) showing the mounting ring having a single rowarray of tissue anchors or staple points projecting axially from themounting ring wherein the staple crosspieces are substantiallytangential with respect to the mounting ring, and (B) showing apartially cut-away view of the mounting ring.

FIGS. 4A and 4B are perspective views of an alternative prosthesis ofthe present invention (A) showing the mounting ring having a doublerowed array of staple points or tissue anchors projecting axially fromthe mounting ring wherein the staple crosspieces are transverse to themounting ring so that a pair of respective staple points on either endof each crosspiece are disposed on opposite sides of the mounting ring,and (B) showing a cut-away view of the mounting ring.

FIGS. 5A and 5B are views of the memory material of a mounting ringshown in the normally open position (A) and in the compressed position(B).

FIGS. 6A-6E are a series of cross-sectional views showing elements ofthe insertion tool and their relationship to a valve prosthesis invarious stages of the implantation of the prosthesis in the lumen of apatient's esophagus.

FIG. 6A is a cross-sectional view of the distal end of the implantationtool showing the relationship of the valve prosthesis, held in acompressed configuration by the collar portion of the overtube, with theballoon and stylet in pre-release position.

FIG. 6B is a side view of the distal end of the implantation toolshowing the relationship of the array of radial tissue anchors to thecollar portion of the overtube, and the balloon/stylet combinationinside the prosthesis.

FIG. 6C is a partial cross-sectional view of the distal end of theimplantation tool showing the relationship of the elements immediatelyupon disengagement of the collar from the prosthesis/stylet combination.

FIG. 6D is a partial cross-sectional view of the prosthesis installationsite in a patient's esophagus showing the balloon in an inflatedcondition and the engagement of the tissue anchors with the tissue ofthe esophagus.

FIG. 6E is a cross-sectional view of the anti-reflux valve prosthesis inplace in a patient's esophagus after the balloon has been deflated andthe insertion tool removed.

FIGS. 7 is a perspective expanded view of the distal end of a circularsurgical stapler for implantation of a valve prosthesis tool showing therelationship of the stapler head to the anvil and the location of tissueengagement vacuum ports.

FIG. 8A is a cross-sectional view of a section of a stapler anvilshowing the relationship of the detent, staple bending notch, theprosthesis mounting ring and skirt to the staple points.

FIG. 8B is a top view of the same section of the stapler anvil as FIG.8A, but without the prosthesis, showing the relationship of the detentchannel and the staple bending notches in the surface of the anvil.

FIG. 9A shows the relationship of the head and anvil of the circularsurgical stapler after the staple head and anvil are approximatelyopposed or spaced apart and receiving the tissue of the esophageal lumenwall upon the application of a vacuum to the stapler assembly.

FIG. 9B shows the relationship of the head and anvil of the circularsurgical stapler after the staple head and anvil are approximatelyopposed or spaced apart for compressing and stapling the received tissueof the lumen wall to the mounting ring of the prosthesis.

FIG. 10 is a perspective view of the surgical stapler showing thestapler head in the distal position with a valve prosthesis received onthe head.

FIG. 11 is a view of a self-anchoring valve prosthesis showing a metalmesh memory material housing containing an anti-reflux valve.

DETAILED DESCRIPTION OF THE INVENTION

As exemplified by the figures, the present invention provides a peroralprosthesis system for treatment of gastroesophageal reflux disease(GERD) in a patient comprising an anti-reflux valve prosthesis, and aperoral implantation tool for perorally inserting and positioning thevalve prosthesis at the distal end of the lumen of the esophagus, andimplanting or fixing the valve prosthesis to the lumen wall.

Referring to FIG. 1, in one preferred embodiment, the anti-reflux valveprosthesis 11 of the present invention has a mounting ring 13. The innerdiameter or central bore of the ring 13 is compatible with orthogradepassage of ingested (or swallowed) material through the lumen of theesophagus. A one-way, anti-reflux valve 21 depends from the mountingring 13 by a valve skirt 22 which is a short section of materialconnecting the mounting ring 13 with the cylinder end of the valve 21.The one-way anti-reflux valve 21 permits the easy passage of ingestedmaterial through the bore of the mounting ring 13 in one direction,while impeding the reflux of stomach content through the bore of themounting ring 13 in the other direction. A suitable anti-reflux valve 21for practicing the present invention is a typical mitral or bicuspidtype valve of a half-flaftened cylindrical shape. Such a shape is easilysuspended from the mounting ring 13 by its cylindrical end. Othervalves, as previously disclosed, are practicable in the presentinvention by the ordinary skilled artisan.

The prosthesis 11 is generally constructed of and/or coated withphysiologically inert materials such as polymeric, ceramic or metallicmaterials. In a preferred embodiment, the exterior surface of theprosthesis has a textured surface to promote adhesion and facilitateanchoring of the prosthesis to the adjacent esophageal wall, while theinterior surfaces are smooth and/or hydrophobic to facilitate theorthograde passage of food and liquids therethrough. Thus, the exteriorof the prosthesis can be made of or coated with microporous ceramic suchas apatite, for example, hydroxyapatite, open- or closed-cell elastomerfoams such as polyurethane, for example, or the like. Smooth materialsfor the interior surfaces of the prosthesis generally include silicone,polytetrafluoroethylene and the like.

Referring to FIGS. 2A-2B, the prosthesis 11 also includes a tissueanchor array 19 for fixing the mounting ring 13 of the prosthesis 11 tothe lumen of the esophagus. The tissue anchor array 19 extends radiallyoutward from the axis of the ring 13. In this embodiment, the tissueanchor array 19 is comprised of barbed spikes 25 for piercing andengaging the lumen wall of the esophagus. The tissue anchor array 19 canbe comprised of at least eight spikes or points, but can have as many asforty or more spikes or points arrayed in a plurality of rows. As shownin FIGS. 3B, 4B, 5A and 5B, the mounting ring 13 is comprised of amemory material 15 shown in the form of a helical spring, and preferablyincludes a compliant and biologically inert coating 17 such as siliconeor polytetrafluoroethylene. The memory material 15 and coating 17 form acombination which may be acted upon by a force and stretched orcompressed from its original shape, but automatically returnssubstantially to the original shape upon removal of the force. FIGS. 5Aand 5B show a memory material 15 of a mounting ring 13 comprising a“key-ring” configuration in the normally open position (A) and in thecompressed position (B).

Referring to FIGS. 6A-6E, in one preferred embodiment, the prosthesissystem of the present invention includes an implantation tool 35 forholding and perorally inserting a prosthesis 11 down the lumen of apatient's esophagus to a position proximate the gastroesophagealjunction, and fixing the prosthesis 11 to the lumen wall. In onepreferred embodiment, the tool 35 comprises a flexible overtube 37, of aconstruction and length suitable for peroral insertion into theesophagus. At one end, the overtube 37 has an integral compressioncollar 39 and at the other end a handle (not shown). A compressioncollar 39 is integral to the collar end 39 of the overtube 37, andprovides a means for releaseably receiving the ring 13 of the prosthesis11 in a compressed configuration. A hollow stylet 43 is slidablycontained (or indwelling) in the length of the overtube 37 from end toend. At the collar 39 of the overtube 37, the stylet 43 has a balloon 45attached. The bladder of the balloon 45 communicates with the hollow ofthe stylet 43, and the balloon 45 is inflatable by pressurizing thehollow of the stylet 43 with a gas or liquid inserted into the hollowfrom the handle end of the tool 35.

Referring to FIG. 7, in another preferred embodiment, an alternativeimplantation tool 49 of the present invention comprises an intralumenalcircular surgical stapler 51, for holding and perorally inserting aprosthesis 11 down the lumen of an esophagus and fixing the prosthesis11 to the lumen wall. The intralumenal stapler 51 has a prosthesisholder 53 and is connected to a vacuum source (not shown) via aperforated tube 52. The stapler 51 comprises an anvil 55 and a head 57having surfaces which are opposed, separated and positionable relativeto each other by means of a central, hollow draw shaft 59 connectedlydisposed between them. The section of the draw shaft 59 between the head57 and anvil 55 is supplied with through vacuum ports 61. The vacuumports 61 communicate the hollow of the shaft 59 with the gap between theanvil 55 and head 57. Further, the hollow of the draw shaft 59communicates with a vacuum source outside the patient, which serves toapply a vacuum to the hollow of the draw shaft 59 which is communicatedto the annular space between the anvil 55 and head 57 by means of theports 61.

Referring to FIGS. 8A and 8B, the anvil 55 has a circular anvil surface63 inset with a detent channel 65 for receiving, holding and releasing,upon application of appropriate force, the mounting ring 13 of theprosthesis 11. The anvil 55 also has a plurality of notches 67 radiallydisposed in pairs, one on either side of the detent 65 for receiving andbending a staple point 71 of a staple 69. The stapler head 57 dispensesstaples 69 radially across the mounting ring 13. The dispensed staples69 pierce the periphery or valve skirt 22 of the prosthesis 11 with atleast one point 71 of each staple. Each point 71 then engages anopposing notch 67 on the anvil surface 63, which bends the staple point71 closing it about the mounting ring 13.

Generally, when the prosthesis 11 is being inserted and positioned inthe esophagus, the stapler 51 is configured with the anvil 55 and head57 in a closed position. In the closed position, the anvil 55 and head57 are drawn closely together upon the draw shaft 59 to enclose themounting ring 13 of the prosthesis 11. When the prosthesis 11 is inposition for installation, the stapler 51 is configured in the fullyopen position, with the anvil 55 and head 57 spaced widely apart on thedraw shaft 59. Referring to FIGS. 9A and 9B, in operation, when theprosthesis 11 has been positioned in the esophagus at the implantationsite using tool 49, and the stapler 51 is configured in the fully openposition (as in FIG. 9A), a vacuum is applied to the interior of thedraw shaft 59 (see FIG. 7). The vacuum is communicated through theperforated tube 52 via the vacuum ports 61. The vacuum pressure at thesite draws the lumenal tissues of the esophagus between the head 57 andanvil 55 of the stapler 51, and up against the tube 52 (see FIG. 9A).

When the tissues have been drawn up against the tube 52, the anvil 55and head 57 are carefully redrawn on shaft 59 to an intermediateposition containing an appropriate thickness of tissues in the gapbetween the head 57 and anvil 55. In this configuration, the lumenaltissue is juxtaposed with the mounting ring 13 of the prosthesis 11 andpositioned for stapling. An appropriate gap contains a sufficientthickness of tissue in which to implant the prosthesis 11, and still beproperly spanned by the staples 69 to engage the notches 67 of the anvil55 when driven by the head 57.

It should be noted that the stapler head 57 does not have to dispensethe staples 69 used to fix the ring 13 to the lumenal tissue.Alternatively, the staples 57 are integral with and radially disposedacross the mounting ring 13 of the prosthesis 11 with their points 71disposed generally parallel to the axis of the prosthesis 11, as shownin FIGS. 3A and 3B and 4A and 4B. In this embodiment, the head 57 isdisposed on the distal end of the tool 49 and has a surface inset withthe detent 65 for releaseably receiving the mounting ring 13 and staples69 combination. The combination of the ring 13 and staples 69 is held ina configuration to engage the notches on the anvil surface. After thestaples 69 have been set and bent against the anvil 55, tnus implantingthe mounting ring 13 in the lumen, the prosthesis 11 is released fromthe detent 65 by the force of the removal of the tool 49 from theesophagus.

In a preferred embodiment, the present invention provides a minimallyinvasive method of surgically treating gastro-esophageal reflux diseasein a patient comprising the steps of inserting the present peroralprosthesis system down the lumen of the esophagus of a patient to betreated; positioning the valve prosthesis 11 of the system at anappropriate position in the esophagus approximate the gastroesophagealjunction of the patient; operating the tool and fixing the valveprosthesis 11 in place in the esophagus of the patient; removing theimplantation tool 51 of the peroral prosthesis system from the esophagusof the patient; and leaving the prosthesis 11 in situ in the lumen ofthe esophagus to treat the patient's gastroesophageal reflux disease.

In a further preferred embodiment, the present invention is a kit fortreating gastroesophageal reflux disease in a patient comprising asterile or sterilizable package (not shown) containing the peroralprosthesis system of the present invention and preferably accompaniedwith instructions for its handling and use.

Referring to FIG. 11, in another preferred embodiment, the presentinvention provides a valve prosthesis 81 comprising a cylindricalhousing 83 constructed of a memory material, in this example a metalmesh. Suspended within the interior of the cylindrical housing is anone-way valve 21. The one-way valve 21 has a mounting ring 13 which isfixed to the interior wall of the housing. Preferably, the mounting ring13 is constructed of a compressible memory material. A feature of thisembodiment is the optional anti-inversion supports 85, one end of whichis fixed to the lower portion of the valve 21 and the other end of whichis fixed to the interior wall of the cylindrical housing 83. Thesupports 85 prevent the valve 21 from inverting.

While the above description contains many specifics, these should not beconstrued as limitations on the scope of the invention, but rather asexemplifications of preferred embodiments thereof. Many other variationsare possible, which would be obvious to one skilled in the art.Accordingly, the scope of the invention should be determined by thescope of the appended claims and their equivalents, and not just by theembodiments.

What is claimed:
 1. A peroral prosthesis system for treatment ofgastroesophageal reflux disease in a patient comprising: an anti-refluxvalve prosthesis comprising: a mounting ring made of an expandable,compressible memory material; an anchor comprising staples for fixingthe mounting ring in the lumen of the esophagus; and a one-way valvedepending from the mounting rings for allowing orthograde passage ofswallowed material, and impeding the passage of gastric content; and aperoral implantation tool for perorally inserting and positioning theprosthesis at a distal end of the lumen of an esophagus, and fixing theprosthesis to the lumen wall of the esophagus, comprising anintralumenal, circular surgical stapler, having an annular spaceconnected to a vacuum source and a prosthesis holder.
 2. The system ofclaim 1 wherein the stapler comprises a head, an anvil axiallypositionable from the head, a perforated tube for drawing the lumen ofthe esophagus between the head and the anvil, and a holder fordisengageably receiving a prosthesis mounting ring.
 3. The system ofclaim 2 wherein the stapler comprises: a stapler head for dispensing anddriving staples; an anvil having a circular surface opposing the staplerhead, and inset with a channel for receiving and holding the mountingring, and a plurality of notches radially disposed in pairs on oppositesides of the channel for receiving and bending staple points; andstaples disposed in the head with points positioned across the mountingring to engage the notches on the anvil surface.
 4. The system of claim2 wherein the stapler comprise: a stapler head for dispensing anddriving staples, having a surface inset with a channel for receiving andholding a mounting ring; staples, having staple points radially disposedacross the mounting ring; and an anvil, having a circular surfaceopposing the stapler head, and a plurality of notches radially disposedin pairs for receiving and bending the staple points.
 5. The system ofclaim 2 wherein the stapler comprises: a stapler head for drivingstaples, having a surface inset with a channel for receiving and holdinga mounting ring; a mounting ring, held in the channel, and having staplepoints integrally incorporated therein and radially projecting from themounting ring; and an anvil, having a circular surface opposing thestapler head, and a plurality of notches disposed for receiving andbending the staple points.
 6. An anti-reflux valve prosthesiscomprising: a mounting ring; an array of at least one row of tissueanchors presenting at least 8 points extending outward from the mountingring, in the direction substantially parallel to the esophagus theanchors having staple points for engaging the lumen wall of an esophagusand fixing the mounting ring in the lumen of the esophagus; and aone-way valve depending from the mounting ring, for allowing orthogradepassage of swallowed material, and impeding the passage of gastriccontent.
 7. The peroral prosthesis system of claim 1 wherein theprosthesis implantation tool comprises: a shaft having a distal staplerend and a proximal handle end; the intralumenal, circular surgicalstapler connected to the distal end of the shaft, the stapler having ahead, an anvil axially positionable from the head, the vacuum sourceadapted for drawing the lumen of the esophagus into the annular spacebetween the head and the anvil, and the prosthesis holder adapted fordisengageably receiving the mounting ring; a handle connected to theproximal end of the shaft, for receiving a vacuum and for manipulatingand operating the stapler; and the shaft having internally disposedmeans for connecting the operation of the handle with the operation ofthe stapler.
 8. The system of claim 7 wherein the stapler furthercomprises: a stapler head for dispensing and driving staples; an anvilhaving a circular surface opposing the stapler head, and inset with achannel for receiving and holding the mounting ring, and a plurality ofnotches radially disposed in pairs on opposite sides of the channel forreceiving and bending staple points; and staples disposed in the headwith points positioned across the mounting ring to engage the notches onthe anvil surface.
 9. The system of claim 7 wherein the stapler furthercomprises: a stapler head for dispensing and driving staples, having asurface inset with a channel for receiving and holding a mounting ring;staples, having staple points radially disposed across the mountingring; and an anvil, having a circular surface opposing the stapler head,and a plurality of notches radially disposed in pairs for receiving andbending the staple points.
 10. The system of claim 7 wherein the staplerfurther comprises: a stapler head for driving staples, having a surfaceinset with a channel for receiving and holding a mounting ring; themounting ring, held in the channel, and having staple points integrallyincorporated therein and radially projecting from the mounting ring; andan anvil, having a circular surface opposing the stapler head, and aplurality of notches disposed for receiving and bending the staplepoints.
 11. A minimally invasive method for surgically treatinggastro-esophageal reflux disease in a patient with the system of claim 1comprising the steps of: perorally inserting the prosthesis received ina distal end of the implantation tool into an esophagus; positioning theprosthesis adjacent to an esophageal junction; fixing the prosthesis inplace in the esophagus of the patient; removing the implantation toolfrom the esophagus; and leaving the valve prosthesis in situ to treatgastro-esophageal reflux disease.
 12. A kit for treatinggastroesophageal reflux disease in a patient comprising: a package; theperoral prosthesis system of claim 1 housed within the package; andoptionally, instructions for use of the peroral prosthesis system. 13.The kit of claim 12 wherein the package and contents are sterile. 14.The anti-reflux valve prosthesis of claim 6 wherein the mounting ringcomprises a helical spring and a biologically inter coating.
 15. Theanti-reflux valve prosthesis of claim 14 wherein the anchors comprise acrosspiece between pairs of staple points and wherein the crosspiecesare disposed within the coating substantially tangentially with respectto the mounting ring.
 16. The anti-reflux valve prosthesis of claim 14wherein the anchors comprise a crosspiece between pairs of staple pointsand wherein the crosspieces are disposed transversely through thecoating so that a pair of respective staple points on either end of eachcrosspiece are disposed on opposite sides of the coating.
 17. Theinvention of any of claim 1, 14, 15, 16 wherein the valve is selectedfrom sleeve valves.